The invention relates to improvements in methods of and in apparatus for admitting liquids into containers, and more particularly to improvements in methods of and in apparatus for admitting metered quantities of liquids (such as carbonated beverages) into bottles or cans. Still more particularly, the invention relates to improvements in methods of and in apparatus which can be utilized with advantage for admission of pressurized liquids into containers wherein the pressure exceeds atmospheric pressure.
It is known to provide a bottle filling apparatus with a plurality of filling units each of which can receive liquid from a vessel and each of which is equipped with a bottle centering and sealing device as well as with a sealable outlet which admits liquid into a properly centered bottle. The vessel contains a relatively large supply of liquid below a cushion of compressed gas, and the apparatus normally embodies a regulator which maintains the top surface of the supply of liquid at, or at least close to, a preselected level. This establishes satisfactory circumstances for admission of desired quantities of liquid into each of a shorter or longer series of successive containers. The vessel can resemble or constitute an annular tank which is driven to rotate about a vertical axis and receives liquid from a centrally located primary source. Thus, the annular tank can turn relative to and about the primary source, and all of the filling units share the angular movements of the tank. Each filling unit is equipped with means for receiving liquid from the tank, with means for dispensing liquid into a properly centered container, with a centering and sealing device as well as with other parts which are needed for controlled admission and dispensing of gaseous and/or hydraulic fluids. Apparatus of the above outlined character can be used for the filling of bottles, cans and/or other types of containers with all kinds of liquids including non-carbonated beverages (such as milk, fruit juices and plain water) as well as carbonated beverages (e.g., beer, club soda and various colas) which must be admitted into internally pressurized containers. The filling units of apparatus for admission of carbonated beverages are equipped with integrated conduits and valves for liquids as well as with integrated pipes and valves for gaseous fluids. An apparatus of the above described character is disclosed, for example, in published German patent application No. 30 25 786. If the apparatus is to be used for the filling of containers with non-pressurized beverages or other non-pressurized liquids, liquid is discharged from the filling units into properly centered empty containers by gravity flow in response to opening of valves which control the outflow of liquid from filling units. If the apparatus is to dispense a pressurized liquid, the filling units admit compressed gas into the properly centered and sealed containers below them so that the pressure in the containers matches the pressure in the tank. The liquid is then permitted to flow into the containers to thereby expel the gases from the containers. As a rule, the expelled gases are caused to flow into the space above the supply of liquid in the tank. To this end, each filling unit is equipped with a gas evacuating pipe having a lower end extending into the upper portion of a properly centered container. The level of the lower end of the gas evacuating pipe determines the upper level of the body of liquid which can be admitted into a container. However, since the capacity of bottles and certain other containers is not constant, i.e., it does not match a preselected value, the aforedescribed mode of selecting the quantity of liquid in filled bottles or other containers does not ensure that each of a short or long series of filled containers invariably stores a predetermined quantity of liquid.
Another drawback of the aforedescribed mode of filling containers to the level of the lower ends of gas evacuating pipes is that the rising body of liquid in a bottle which is in the process of receiving liquid is likely to wet the lower ends of the pipes. Such liquid is atomized during admission of gas into the next bottle and is likely to cause foaming which is undesirable in many or most instances.